We study a universal property of Sp(2) in the category of 3-local homotopy associative, homotopy commutative H-spaces. We show that while Sp(2) fails to be universal in the full category, there is a subcategory in which it is universal for its 7-skeleton.
Homology, Homotopy and Applications, Vol. 11 (2009), No. 1, pp.1-15.